Developers tell Gamasutra that working with the Wii U's touchscreen controller has been a challenge of making games for the console -- not least because players aren't sure where to focus.

"One thing that has been an interesting problem is a physical one: asking players to iterate between looking ahead at a TV and down at their hands requires both physiological and mental mode shifting," says Albert Reed, CEO and co-founder of Demiurge Studios. The team is working on the Wii U version of Gearbox's Aliens: Colonial Marines.

"Making sure our designs provide a usable 'flow' between these two gameplay positions has been interesting," says Reed.

Diego Fernandez Bravo, Ubisoft Paris producer on launch game Rabbids Land agrees -- though his team had to meet the challenge in a slightly different way due to the fact that they were creating a party game.

The "challenge was to keep the interest of the people watching the game when it's not their turn to play, and still be able to understand what is happening in the game, since they don't have easy access everything that is happening on the Wii U Gamepad," says Fernandez Bravo.

"We had to take into consideration how to make the game interactive and fun both on and off screen."

These quotes come as part of a feature in which the developers of these games, as well as Mass Effect 3, ZombiU and Darksiders IIsound off about what it's like to develop for Nintendo's new console, which is due to be released in North America this Sunday.